On inverter side of Xingren to Baoan HVDC link， grounding electrode line is assembled on the same tower with HVDC line. When HVDC line experiences a lightning， the induced over voltage on grounding electrode line will cause a ground fault. If one of the pole blocks and fails to restart， then the unbalanced current protection for parallel grounding electrode lines actuates to block another pole operation. In order to prevent such a phenomenon， a method of inserting DC breakers into both grounding electrode lines is proposed. The control and protection strategy of the grounding electrode line is adjusted correspondingly.